A good place to start is the multiple ways Hawkes Bay Regional Council and Hastings District Council work together to deliver safe drinking water to the public. The picture below is a schematic showing how the different activities in each organisation fit together for the purposes of providing drinking water. It's not the total picture as the Ministry of Health play a very important role too.
For the purposes of the Inquiry HBRC and HDC interact in three ways to deliver drinking water to residents.
1. Water Supplier
Starting with the main sequence at the bottom note that, in effect, HBRC supply source water to HDC. It's a natural resource but HBRC have total control over who gets to use it. So HBRC are continuously updating their knowledge of the water resource of the region: how much there is and how good it is. Using this knowledge they update their regional plan which tells them, essentially, what consents they can issue for water use.
Little known is an additional legal requirement, the National Environmental Standard for Sources of Human Drinking Water. This forces HBRC to operate its plan in such a way as to ensure clean enough water gets to HDC for drinking purposes. Because HDC wasn't treating the water it extracted in Havelock North, HBRC had to ensure uncontaminated groundwater was available at the bores. This standard also required HBRC to include emergency situations in its consenting decisions.
2. Science Provider
The second relationship is the science that HBRC supplies to HDC to help them in their planning and management of the water supply. District councils don't do their own hydrogeology, they rely on regional councils to provide them with the information they need to understand the risks of operating their supplies.
The key decisions HDC made about where to source water, how to treat it and how to manage the risks around their system - remembering all of these decisions have big price tags attached to them - were based on the information provided by HBRC.
Finally, HBRC issues the consent to HDC to allow them to take water for a public water supply. And they monitor compliance with the consent.
HBRC's regulatory role is restricted to the elements of the water take that impact water quantity generally and that could impact downstream water quality. They have no role at all in regulating the delivery of safe drinking water.
In the original 2008 consent issued to HDC, HBRC attached 21 conditions. 20 of them covered issues to manage the amount of water taken. The final condition required HDC to secure its wellheads. HBRC has to try to manage all activities - not just public drinking water supplies - to ensure that human activity does not pollute or degrade the natural water resource. So this condition is not attached specifically because it is for a source of drinking water.
Is Hawkes Bay Regional Council About to Score an Own Goal?
Having decided to prosecute HDC for a breach of consent conditions HBRC presumably will argue in court that HDC failed to comply with this condition:
21. All works and structures relating to this consent shall be designed and constructed to conform to the best engineering practices and at all times maintained to a safe and serviceable standard.
What any of those general requirements might mean in practice is defined by the Ministry of Health who are, in fact, the primary regulator in this case. But Ministry of Health are not a party to this prosecution. So HBRC are on their own, not alleging that the condition of the well-heads was the cause of the gastro outbreak only that HDC didn't maintain the well-heads properly.
If HDC decide to defend themselves they will question how enforceable such a vague condition is. They will ask HBRC to clarify what these practices were intended to be, how they were communicated to HDC, and why HBRC ticked off these structures as compliant year after year. HDC can point to the fact that MoH didn't have any security issues with the well-heads when they issued HDC with a water supply grading.
HDC also have a good case that whatever they did or didn't do was reasonable in the context of how HBRC was carrying out its regulatory function. In particular - and this will crop up again in the inquiry - whether HDC could reasonably rely on regulatory approval given year after year by HBRC.
The spotlight could well turn onto how well HBRC carried out its regulatory duties and should spill over - whether in court or in the inquiry - to how well HBRC carried out its statutory obligations to protect the water source for Havleock North drinking water.
I suspect HBRC would have been better off going through the Inquiry in a collaborative manner hoping that not too much attention would head their way. Too late now.